Cosmetic brush



FIG. 1 is a perspective view of the cosmetic brush;

FIG. 2 is a side view thereof;

FIG. 3 is an enlarged top view thereof; and,

FIG. 4 is an enlarged bottom view thereof.

The broken lines illustrate portions of the cosmetic brush and form no part of the claimed design. 

CLAIM The ornamental design for a cosmetic brush, as shown and described. 